JP6072610B2 - Vehicle control device - Google Patents

Description

  The present invention relates to a vehicle control device in which a clutch is provided on each of an input side and an output side of a transmission.

  Conventionally, a vehicular control device in which a clutch is provided on each of an input side and an output side of a transmission is known, and an example thereof is described in Patent Document 1. The vehicle control device described in Patent Document 1 is provided with a continuously variable transmission from an engine (power source) to drive wheels, and a forward / reverse switching mechanism is provided between the engine and the continuously variable transmission. ing. The forward / reverse switching mechanism is selectively controlled by a single pinion type planetary gear mechanism, a clutch (first clutch) that connects or releases the sun gear and ring gear of the planetary gear mechanism, and a carrier that supports the pinion gear of the planetary gear mechanism. And a brake for powering. The sun gear is connected to the engine, and the ring gear is connected to the input shaft of the continuously variable transmission. A starting clutch (second clutch) is provided between the continuously variable transmission and the drive wheels.

  When the shift lever is in the drive range, the clutch is engaged, the brake is released, and the sun gear and the input shaft of the continuously variable transmission rotate integrally. On the other hand, when the position of the shift lever is in the reverse range, the brake is engaged and the clutch is released. Therefore, the carrier becomes a reaction force element, and the ring gear rotates in the opposite direction with respect to the rotation direction of the sun gear. Note that the vehicle control device described in Patent Document 1 determines the failure of the control valve that controls the engagement force of the starting clutch.

JP 2001-208177 A

  However, since there is no description about the failure of the 1st clutch arrange | positioned in the upstream of a continuously variable transmission in the vehicle control apparatus described in patent document 1, the 2nd clutch is engaged. In this state, when the first clutch disposed upstream of the continuously variable transmission fails, there is a problem that the engine becomes a rotating inertial mass body and the driving force changes and is felt as a shock.

  An object of the present invention is to provide a vehicle control device that can suppress a sudden change in driving force when a failure occurs in which the torque capacity of a first clutch disposed upstream of a transmission increases. is there.

  The present invention relates to a transmission provided between a power source and a drive wheel, a first clutch provided between the power source and the transmission, and an actuator for controlling a torque capacity of the first clutch. And a second clutch provided between the transmission and the drive wheel, wherein the first clutch has a structure in which a torque capacity increases when the actuator fails. A failure detection unit that detects whether the actuator has failed, and a clutch control unit that reduces the torque capacity of the second clutch when it is detected that the actuator has failed.

  According to the present invention, when the actuator fails, the torque capacity of the second clutch is reduced. Accordingly, it is possible to suppress a sudden change in the driving force in the driving wheels of the vehicle.

It is a schematic diagram which shows the structural example of the vehicle to which this invention is applied. It is a schematic diagram which shows the structure of the control apparatus for vehicles which is one embodiment of this invention. It is a flowchart which shows an example of the control logic performed by the control unit of FIG. It is a figure which shows an example of the time chart corresponding to the flowchart of FIG.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a schematic diagram illustrating a configuration example of a vehicle 10 to which the present invention is applied, and FIG. 2 is a schematic diagram illustrating a configuration of a control device of the present invention. The power train of the vehicle 10 includes an engine 11 as a first power source and a traveling motor 12 as a second power source. The engine 11 is a power source that burns fuel and converts its thermal energy into kinetic energy. The traveling motor 12 is a power source that converts electrical energy into kinetic energy. The engine 11 may be any of a gasoline engine, a diesel engine, a liquefied petroleum gas engine, and the like.

  That is, the vehicle 10 is a hybrid vehicle provided with two types of power sources having different power generation principles. The power train has a continuously variable transmission 13 as a variator. The continuously variable transmission 13 includes a primary pulley 14 and a secondary pulley 15. The engine 11 is connected to the end of the primary pulley 14 in the longitudinal direction via a torque converter 16.

  The torque converter 16 includes a pump impeller 88 connected to the crankshaft 22, a turbine runner 90 connected to the torque transmission shaft 89, and a stator. The torque converter 16 is a fluid transmission device that transmits power by the kinetic energy of hydraulic oil, and can amplify torque by the action of the stator.

  On the other hand, the traveling motor 12 is connected to the other end of the primary pulley 14 in the longitudinal direction. A power storage device is connected to the stator 78 of the traveling motor 12 via an inverter 79. The traveling motor 12 is a so-called motor generator that functions as a generator and an electric motor. For this reason, the control which supplies the electric power of an electrical storage apparatus to the motor 12 for a drive, and starts as a motor, and the control which starts the motor 12 for a drive as a generator with the motive power of the primary shaft 32, and accumulate | stores the generated electric power in an electrical storage apparatus And can be executed.

  A drive wheel output shaft 18 is coupled to the secondary pulley 15 via a fuse clutch 17. Drive wheels 21 are connected to the drive wheel output shaft 18 via a differential mechanism 19 and an axle shaft 20. Further, an integrated starter generator (ISG) 24 is connected to the crankshaft 22 of the engine 11 via a drive chain 36. When the engine 11 is stopped, the crankshaft 22 is cranked by the torque of the ISG 24, and the fuel injection control and the ignition control are performed by the engine 11, so that the engine 11 can be rotated autonomously. That is, 1SG24 is a starter generator motor having a function of starting the engine 11.

  The power transmission path between the torque transmission shaft 89 and the primary shaft 23 of the continuously variable transmission 13 is provided with an input clutch 30 that can be switched between a released state and an engaged state. The input clutch 30 may be either a multi-plate clutch or a single plate clutch. The input clutch 30 may be either a wet clutch or a dry clutch. A hydraulic chamber 92 that controls the torque capacity of the input clutch 30 is also provided. The input clutch 30 is switched between an engaged state and a released state by controlling the hydraulic pressure of the hydraulic chamber 92 to adjust the torque capacity. The input clutch 30 is engaged when the hydraulic pressure in the hydraulic chamber 92 increases, and is released when the hydraulic pressure in the hydraulic chamber 92 decreases.

  A continuously variable transmission 13 provided in a power transmission path from the engine 11 and the traveling motor 12 to the drive wheels 21 is connected to a primary shaft 32 connected to the rotor shaft 31 of the traveling motor 12 and parallel to the primary shaft 32. Secondary shaft 33. A primary pulley 14 is provided on the primary shaft 32, and a primary chamber 34 is defined on the back side of the primary pulley 14. The primary pulley 14 has a movable sheave that can move in the longitudinal direction of the primary shaft 32 and a fixed sheave that cannot move in the longitudinal direction of the primary shaft 32. The hydraulic pressure in the primary chamber 34 acts on the back surface of the movable sheave of the primary pulley 14.

  The secondary shaft 33 is provided with a secondary pulley 15. The secondary pulley 15 includes a movable sheave that can move in the longitudinal direction of the secondary shaft 33, and a fixed sheave that cannot move in the longitudinal direction of the secondary shaft 33. Have A secondary chamber 35 is defined on the back side of the secondary pulley 15. The hydraulic pressure in the secondary chamber 35 acts on the back surface of the movable sheave of the secondary pulley 15. Further, a return spring is provided in the secondary chamber 35, and the return spring generates a force in a direction to bring the movable sheave of the secondary pulley 15 closer to the fixed sheave.

  Further, a drive chain 36 is wound around the primary pulley 14 and the secondary pulley 15. For this reason, the secondary pulley 15 applies a clamping pressure to the drive chain 36 by the force of the return spring.

  When the amount of hydraulic oil in the primary chamber 34 is controlled, the movable sheave of the primary pulley 14 moves in the longitudinal direction based on the relationship between the tension of the drive chain 36 and the thrust applied to the movable sheave of the primary pulley 14. The wrapping diameter of the drive chain 36 changes. For example, when the amount of hydraulic oil in the primary chamber 34 increases, the winding diameter of the drive chain 36 in the primary pulley 14 increases, and the continuously variable transmission 13 performs an upshift.

  On the other hand, when the amount of hydraulic oil in the primary chamber 34 decreases, the winding diameter of the drive chain 36 in the primary pulley 14 decreases, and the continuously variable transmission 13 performs a downshift. In this way, the ratio between the rotational speed of the primary shaft 32 and the rotational speed of the secondary shaft 33, that is, the gear ratio can be changed steplessly.

  Further, when the hydraulic pressure in the secondary chamber 35 is controlled, the clamping pressure applied to the drive chain 36 from the secondary pulley 15 changes, and the torque capacity of the continuously variable transmission 13 can be controlled.

  As described above, the fuse clutch 17 is provided between the continuously variable transmission 13 and the drive wheel 21. The fuse clutch 17 is a mechanism that controls the torque capacity between the secondary shaft 33 and the drive wheel output shaft 18. The fuse clutch 17 may be either a multi-plate clutch or a single-plate clutch. The fuse clutch 17 may be either a wet clutch or a dry clutch. The fuse clutch 17 has a torque capacity controlled by hydraulic control. The fuse clutch 17 has a friction material attached to the surface of a metal disk.

  The fuse clutch 17 is a friction clutch that automatically enters a slip state when a disturbance occurs, for example, when the driving wheel 21 slips and the torque input to the fuse clutch 17 exceeds a set torque. The fuse clutch 17 functions as a torque limiter that prevents the drive chain 36 from slipping due to excessive torque being input to the continuously variable transmission 13.

  A mechanical pump 41 such as a trochoid pump is provided to supply hydraulic oil to the oil required parts such as the continuously variable transmission 13 and the torque converter 16 described above. In addition, a valve unit 42 is provided to control the flow rate or pressure of the hydraulic oil supplied to the oil required part. The valve unit 42 includes a flow control valve that controls the amount of hydraulic oil in the primary chamber 34, a pressure control valve that separately controls the hydraulic pressure in the secondary chamber 35, and the hydraulic chambers 91 and 92, and a hydraulic pressure that connects these valves and an oil pan. Circuit and the like.

  The pressure control valve is a duty solenoid valve that can control the output hydraulic pressure by controlling a duty ratio that is a ratio between energization and non-energization. The flow control valve is an on / off solenoid valve that controls the amount of hydraulic oil by switching between opening and closing.

  The valve unit 42 includes a failure detection sensor 97 a that detects a failure of the duty solenoid valve 97 that controls the hydraulic pressure in the hydraulic chamber 92, and a signal from the failure detection sensor 97 a is input to the control unit 73. The failure detection sensor 97a detects a failure such as disconnection or leakage of a wire supplying power to the duty solenoid valve 97 based on a voltage of a circuit supplying power to the duty solenoid valve 97, for example. When electric leakage occurs, the electric power of the power storage device is not supplied to the duty solenoid valve 97 and falls to the ground. The input clutch 30 according to the present embodiment has a structure in which the torque capacity is increased when the duty solenoid valve 97 is not supplied with electric power when engaged.

  The hydraulic oil discharged from the mechanical pump 41 when the mechanical pump 41 is driven is supplied to the continuously variable transmission 13, the torque converter 16, the fuse clutch 17, the input clutch 30, and the like through the valve unit 42. Specifically, the flow rate of the hydraulic oil in the primary chamber 34, the hydraulic pressure of the hydraulic oil in the secondary chamber 35, and the hydraulic pressures in the hydraulic chambers 91 and 92 are controlled separately.

  The mechanical pump 41 includes an outer rotor 43 and an inner rotor 44 incorporated in the outer rotor 43. A rotor shaft 45 and a driven sprocket 46 are attached to one end of the inner rotor 44. A drive sprocket 48 is attached to the primary shaft 32 parallel to the rotor shaft 45 via a one-way clutch 47.

  A chain 49 is wound around the drive sprocket 48 and the driven sprocket 46, and the primary shaft 32 and the inner rotor 44 are connected via a chain mechanism 50. As described above, the mechanical pump 41 is connected to the primary shaft 32 that constitutes a part of the power transmission path 52 via the first drive system 51 configured by the chain mechanism 50. The power transmission path 52 includes the continuously variable transmission 13, the fuse clutch 17, the drive wheel output shaft 18, the differential mechanism 19, the axle shaft 20, and the like.

  A rotor shaft 61 and a driven sprocket 62 are attached to the other end of the inner rotor 44 of the mechanical pump 41. A drive sprocket 66 is attached to a hollow shaft 64 fixed to the pump shell of the torque converter 16 and parallel to the rotor shaft 61 via a one-way clutch 65. A chain 67 is wound around the drive sprocket 66 and the driven sprocket 62, and the hollow shaft 64 and the inner rotor 44 are connected via a chain mechanism 68. Thus, the mechanical pump 41 is connected to the crankshaft 22 of the engine 11 via the second drive system 69 configured by the chain mechanism 68 and the torque converter 16.

  The one-way clutch 47 constituting the first drive system 51 transmits power to the inner rotor 44 from the primary shaft 32 that rotates in the forward rotation direction, while blocking power transmission in the opposite direction. Similarly, the one-way clutch 65 constituting the second drive system 69 transmits power to the inner rotor 44 from the hollow shaft 64 that rotates in the forward rotation direction, while blocking power transmission in the opposite direction.

  That is, when the primary shaft 32 rotates faster than the hollow shaft 64, the mechanical pump 41 is driven by the primary shaft 32 on the traveling motor 12 side, while the hollow shaft 64 rotates faster than the primary shaft 32. The mechanical pump 41 is driven by the hollow shaft 64 on the engine 11 side.

  The forward rotation direction of the primary shaft 32 is the rotation direction of the primary shaft 32 during forward travel. The forward rotation direction of the hollow shaft 64 is the rotation direction of the crankshaft 22 when the engine is operating.

  As described above, the primary shaft 32 and the hollow shaft 64 are connected to the inner rotor 44 of the mechanical pump 41. Thus, in the parallel travel mode in which the engine 11 is driven, the mechanical pump 41 can always be driven by the engine 11, and the hydraulic oil discharged from the mechanical pump 41 is supplied to the continuously variable transmission 13, the torque converter 16, and the input clutch. The hydraulic chamber 91 for controlling the torque capacity of 30 and the hydraulic chamber 92 for controlling the torque capacity of the fuse clutch 17 can be supplied.

  The vehicle control device 70 can select the motor travel mode or the parallel travel mode as the travel mode of the vehicle 10. When the motor travel mode is selected, the input clutch 30 is released, and the power transmission path between the engine 11 and the primary shaft 32 is interrupted. When the motor travel mode is selected, the engine 11 is stopped, and when the accelerator pedal is depressed, the travel motor 12 is activated as an electric motor, and the torque of the travel motor 12 is transmitted to the drive wheels 21. To do.

  When the motor travel mode is selected and the accelerator pedal is returned while the vehicle 10 is traveling, the kinetic energy due to the repulsive travel of the vehicle 10 passes through the drive wheel output shaft 18 and the continuously variable transmission 13. Since it is transmitted to the primary shaft 32, the traveling motor 12 can be activated as a generator to apply a regenerative braking force to the drive wheels 21.

  On the other hand, when the parallel travel mode is selected as the travel mode of the vehicle 10, the input clutch 30 is engaged, and the torque of the engine 11 can be transmitted to the drive wheels 21 via the continuously variable transmission 13. it can. When the parallel travel mode is selected, both the torque of the engine 11 and the torque of the travel motor 12 can be transmitted to the drive wheels 21. Whether only the torque of the engine 11 is transmitted to the drive wheels 21 or whether both the torque of the engine 11 and the torque of the traveling motor 12 are transmitted to the drive wheels 21 depends on the target driving force obtained from the vehicle speed, the accelerator opening, etc. The control unit 73 makes a determination based on conditions such as the fuel consumption of the engine 11 and the charge amount of the power storage device connected to the traveling motor 12.

  The vehicle control device 70 is configured to switch between the motor travel mode and the parallel mode when the driver operates the mode switch, or to change the state of the vehicle 10 without operating the mode switch. Any of the configurations that can be switched automatically in response to this may be used. Therefore, the control unit 73 controls the engine 11 and the traveling motor 12 based on the charge amount of the power storage device connected to the traveling motor 12, the target output obtained from the target driving force, the fuel consumption of the engine 11, and the like. Stores maps, data, etc.

  When the motor travel mode is selected, the engine 11 is stopped, and the travel motor 12 is driven, the mechanical pump 41 can be driven by the power of the primary shaft 32. Thus, the mechanical pump 41 is driven by the power of the primary shaft 32 provided on the input side of the continuously variable transmission 13.

  By the way, when the motor travel mode is selected and the vehicle 10 is stopped, the mechanical pump 41 is stopped together with the primary shaft 32. However, even when the vehicle 10 is stopped, it is necessary to supply hydraulic oil to oil-required parts such as the continuously variable transmission 13 and the hydraulic chambers 91 and 92.

  Therefore, the vehicle control device 70, when the motor traveling mode is selected and the vehicle 10 is stopped, or when the hydraulic oil discharge amount of the mechanical pump 41 is small, such as during deceleration of the vehicle 10, An electric pump 72 driven by an electric motor 71 is provided in order to secure the basic hydraulic pressure of the hydraulic circuit of the valve unit 42, that is, the line pressure.

  As shown in FIG. 2, the vehicle control device 70 includes a control unit 73 that controls the electric pump 72, the gear ratio and torque capacity of the continuously variable transmission 13, the engine 11, the traveling motor 12, the ISG 24, and the like. The control unit 73 includes a CPU that calculates control signals and the like, a ROM that stores control programs, arithmetic expressions and map data, and a RAM that temporarily stores data.

  The control unit 73 includes a signal from a wheel speed sensor 74 that detects the rotation speed of the drive wheel 21, a signal from a motor rotation sensor 76 that detects the rotation speed of the rotor 75 included in the traveling motor 12, and a depression of the brake pedal by the driver. A signal of the brake switch 77 for detecting the situation, a signal of the primary axis sensor 93 for detecting the rotation speed of the primary shaft 32, a signal of the secondary axis sensor 94 for detecting the rotation speed of the secondary shaft 33, and the depression amount of the accelerator pedal are detected. A signal from the accelerator opening sensor, a signal from the turbine speed sensor 95 that detects the speed of the torque transmission shaft 89, a signal from the speed sensor 96 that detects the speed of the drive wheel output shaft 18, and the like are input.

  The control unit 73 controls the rotational speed, regenerative torque, power running torque, and the like of the traveling motor 12 via the inverter 79. The regenerative torque is a torque when starting the traveling motor 12 as a generator, and the power running torque is a torque when starting the traveling motor 12 as an electric motor.

  In the vehicle 10 having the above configuration, the vehicle 10 travels in a state where the motor travel mode is selected, the engine 11 is stopped, and the input clutch 30 is released, and then the vehicle speed is gradually decreased to a predetermined value. If it is less than that, the discharge pressure of the mechanical pump 41 decreases as the rotational speed of the primary shaft 32 decreases. For this reason, in the discharge hydraulic pressure of the mechanical pump 41, there is a possibility that the actual line pressure of the hydraulic circuit is less than the target line pressure corresponding to the condition of the oil required part. The control unit 73 drives the electric pump 72 in such a case.

  When the electric pump 72 is driven, the hydraulic oil discharged from both the mechanical pump 41 and the electric pump 72 is supplied to the valve unit 42. Therefore, the line pressure in the hydraulic circuit of the valve unit 42 can be ensured. More specifically, the actual line pressure in the valve unit 42 can be controlled to the target line pressure according to the conditions of the oil required part.

  Next, an example of the control logic performed by the control unit 73 will be described based on the flowchart of FIG. In the control logic shown in the flowchart of FIG. 3, the accelerator pedal is depressed to select the motor travel mode, the engine 11 is stopped, the input clutch 30 is released, and the torque of the travel motor 12 is increased. It is executed when it is transmitted to the drive wheel 21.

  First, in step S10, the control unit 73 determines whether or not the input clutch 30 has failed. The control unit 73 indirectly determines whether or not the input clutch 30 has failed based on a signal from the failure detection sensor 97a.

  If the control unit 73 determines that the input clutch 30 is normal and No in step S10, the control unit 73 learns the fuse clutch 17 using parameters such as the rotational speed difference between the secondary shaft 33 and the drive wheel output shaft 18 in step S12. Calculate the value OUTTRQLRN. The technical meaning of this learned value OUTTRQLRN will be described later. Further, “output clutch” described in the flowchart of FIG. 3 means the fuse clutch 17.

  The control unit 73 obtains the target clutch pressure OUTTRQ in step S12 following step S11, and ends the control routine of FIG. The target clutch pressure OUTTRQ is a target value of the hydraulic pressure in the hydraulic chamber 91, and the target clutch pressure OUTTRQ can be obtained by, for example, Expression (1).

OUTTRQ = Reference pressure + Learning value OUTTRQLRN ・ ・ ・ Equation (1)
In Equation (1), the reference pressure is a value determined from the torque input to the continuously variable transmission 13, the gear ratio of the continuously variable transmission 13, and the like. This reference pressure is a value that can prevent the fuse clutch 17 from slipping when the torque output from the continuously variable transmission 13 is transmitted to the drive wheel output shaft 18. Further, the reference pressure is set such that the drive chain 36 slips in the continuously variable transmission 13 when an excessive torque is input to the drive wheel output shaft 18 due to disturbance in the vehicle 10, for example, slip of the drive wheel 21. The value is to slide the fuse clutch 17 before it occurs.

  Next, the technical meaning of the learning value OUTTRQLRN will be described. If the friction coefficient of the friction material of the fuse clutch 17 is equal to or greater than a predetermined value, the torque capacity of the fuse clutch 17 can be controlled to the target torque capacity when the hydraulic pressure in the hydraulic chamber 91 is used as a reference pressure. That is, it is possible to prevent the fuse clutch 17 from slipping when transmitting the torque output from the continuously variable transmission 13 to the drive wheel output shaft 18. Further, when the drive wheel 21 slips or the like and excessive torque is input to the drive wheel output shaft 18, the fuse clutch 17 is slid before the drive chain 36 slips in the continuously variable transmission 13. Can do.

  However, if the friction material of the fuse clutch 17 is worn due to secular change and the friction coefficient of the friction material becomes smaller than a predetermined value, the fuse clutch 17 can be controlled even if the hydraulic pressure in the hydraulic chamber 91 is controlled to the reference pressure. The torque capacity is less than the target torque capacity. Then, when the torque output from the continuously variable transmission 13 is transmitted to the drive wheel output shaft 18, the fuse clutch 17 may slip.

  The control unit 73 obtains the learning value OUTTRQLRN as an increase in the pressure applied to the reference pressure in order to increase the torque capacity of the fuse clutch 17 and avoid the above-described inconvenience.

  In this way, the control unit 73 obtains the target clutch pressure OUTTRQ by adding the reference pressure and the learned value OUTTRQLRN in step S12. Therefore, even if the friction coefficient of the friction material of the fuse clutch 17 becomes small, it is possible to prevent the fuse clutch 17 from slipping with the torque transmitted from the continuously variable transmission 13 to the fuse clutch 17.

  On the other hand, if the control unit 73 determines Yes in step S10, the control unit 73 performs control to reset the learning value OUTTRQLRN for controlling the torque capacity of the fuse clutch 17 in step S13, that is, to set it to “0 (zero) Mpa”. Proceed to S12.

  Thus, when it progresses to step S12 via step S13, the target clutch pressure OUTTRQ becomes a reference pressure temporarily temporarily in effect. That is, the torque capacity of the fuse clutch 17 is the lowest value at which power can be transmitted. For this reason, even if the input clutch 30 fails and is engaged, the power transmission system including the engine 11 becomes a rotary inertia mass body, and even if the torque transmitted to the secondary shaft 33 fluctuates, the torque fluctuation is driven by the drive wheels 21. Can be prevented from being transmitted to. In addition, it progresses to step S12 via step S13, the target clutch pressure OUTTRQ calculated | required by the step S12 is raised with progress of time, and is finally returned to the value when the input clutch 30 is normal. .

  Next, an example of a time chart corresponding to the control logic shown in the flowchart of FIG. 3 will be described based on FIG. First, before the time t1, the state of the input clutch is “OK”, that is, it is determined to be normal. Further, the engagement pressure of the input clutch is controlled to “0 Nm”.

  Further, since the input clutch is released, there is a predetermined rotational speed difference between the rotational speed of the primary shaft and the turbine rotational speed. Further, the vehicle is traveling at a constant vehicle speed by the torque of the traveling motor, and the longitudinal acceleration G of the vehicle is “0”. Further, the target clutch pressure of the fuse clutch is a value obtained by adding a learning value to the reference pressure. Furthermore, the rotational speed difference between the secondary shaft and the drive wheel output shaft is “0”.

  At time t1, the input clutch pressure increases, and it is determined that the state of the input clutch is NG, that is, a failure. The input clutch pressure is the hydraulic pressure in the hydraulic chamber 92. Moreover, the turbine rotation speed has begun to rise after time t1. Further, since the learning value is reset at time t1, the target clutch pressure of the fuse clutch becomes the reference pressure. For this reason, after the time t1, the rotational speed of the secondary shaft decreases, and the rotational speed difference between the secondary shaft and the drive wheel output shaft increases.

  After time t2, the oil pressure of the input clutch becomes substantially constant, and the input clutch is engaged. For this reason, the rotation speed of the primary shaft matches the turbine rotation speed. In addition, after time t1, since the target clutch pressure of the fuse clutch is set to the basic pressure, it is obtained as a value of the basic pressure + learning value as time elapses and is obtained so as to gradually increase. The torque capacity of the fuse clutch gradually increases. Therefore, after time t2, the rotational speed difference between the secondary shaft and the drive wheel output shaft decreases.

  Further, after time t3, the rotational speed difference between the secondary shaft 33 and the drive wheel output shaft 18 becomes “0”, and at time t4, the target clutch pressure of the fuse clutch becomes the same as the target clutch pressure before time t1. ing.

  As described above, the control unit 73 is in a state where the motor travel mode is selected, the engine 11 is stopped, the input clutch 30 is released, and the torque of the travel motor 12 is transmitted to the drive wheels 21. Thus, when a failure occurs in which the torque capacity of the input clutch 30 increases, control for temporarily reducing the torque capacity of the fuse clutch 17 is executed.

  For this reason, even when the input clutch 30 to be released fails and is engaged, and the power transmission system including the engine 11 becomes the inertia mass body of the primary shaft 32, the fluctuation of the torque transmitted to the drive wheels 21 Can be suppressed. Therefore, it can suppress that the driving force which generate | occur | produces with the driving wheel 21 changes, and can reduce the shock which a driver | operator experiences.

  Further, when a failure occurs in which the input clutch 30 is engaged, the target clutch pressure is reduced to the reference pressure without completely releasing the fuse clutch 17. Thereafter, control for increasing the target clutch pressure of the fuse clutch 17 obliquely as shown in the time chart of FIG. 4 is executed. Therefore, the torque capacity of the fuse clutch 17 can be restored to the value before time t1 without the driver feeling uncomfortable.

  The broken line shown in the time chart of FIG. 4 shows a comparative example corresponding to the control of this embodiment. In this comparative example, the target clutch pressure of the fuse clutch is controlled to be constant similarly to the time before time t1 after time t1 when the failure in which the input clutch is engaged occurs. For this reason, the difference between the rotational speed of the secondary shaft and the rotational speed of the drive wheel output shaft is “0” after the time t1, and the longitudinal acceleration G of the vehicle changes.

  That is, the acceleration in the longitudinal direction of the vehicle goes back and forth alternately between positive and negative with “0” as a boundary. This is because the power transmission shaft connected to the engine is twisted in a predetermined direction around the center line in the rotational direction, restored to its original shape by its restoring force, and then twisted in the reverse direction for a certain period of time. Because it repeats in between.

  The correspondence between the configuration described in the present embodiment and the configuration of the present invention will be described. The input clutch 30 is the first clutch of the present invention, the fuse clutch 17 is the second clutch of the present invention, and the primary clutch The shaft 32 is the torque transmission element of the present invention, the drive chain 36 corresponds to the winding transmission member of the present invention, and the duty solenoid valve 97 corresponds to the actuator of the present invention. The control unit 73 is a failure detection unit and a clutch control unit of the present invention. Further, the reference pressure corresponds to the reference value of the present invention.

  It goes without saying that the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the scope of the invention. For example, although a chain drive type continuously variable transmission is shown as the continuously variable transmission, the continuously variable transmission in the present invention includes a belt drive type or traction drive type continuously variable transmission. In the belt drive type continuously variable transmission, the belt wound around the primary pulley and the secondary pulley corresponds to the winding transmission member of the present invention. The traction drive type continuously variable transmission includes an input disk and an output disk, and a power roller interposed between the input disk and the output disk. The continuously variable transmission of the present invention can change the gear ratio steplessly without reducing the torque capacity between the input element and the output element.

  Furthermore, the drive wheel of the present invention may be at least one of the front wheel and the rear wheel. Further, the vehicle targeted by the present invention includes a vehicle that uses a flywheel system as a power source instead of the driving motor. Further, the vehicle targeted by the present invention includes a vehicle that uses a hydraulic motor as a power source instead of the traveling motor. Furthermore, the torque transmission element of the present invention includes a rotating shaft, a gear, and the like.

  Furthermore, the first clutch and the second clutch of the present invention include an electromagnetic clutch whose torque capacity is controlled by electromagnetic force, in addition to a hydraulically controlled clutch whose torque capacity is controlled by hydraulic pressure. In this case, both the reference value and the learning value are represented by electromagnetic force.

DESCRIPTION OF SYMBOLS 10 Vehicle 11 Engine 12 Driving motor 13 Continuously variable transmission 17 Fuse clutch 21 Drive wheel 30 Input clutch 73 Control unit 97 Duty solenoid valve

Claims (3)

A transmission provided between the power source and the drive wheel; a first clutch provided between the power source and the transmission; an actuator for controlling a torque capacity of the first clutch; A vehicle control device having a second clutch provided between the machine and the drive wheel,
The first clutch has a structure in which a torque capacity increases when the actuator fails,
A failure detector for detecting whether the actuator has failed; and
A clutch controller that reduces the torque capacity of the second clutch when it is detected that the actuator has failed;
A vehicle control device. The vehicle control device according to claim 1,
The power source is an engine;
The transmission is a continuously variable transmission including a winding transmission member;
An electric motor coupled to a power transmission path from the first clutch to the continuously variable transmission is provided;
The failure detection unit performs control to reduce the torque capacity of the first clutch by the normal actuator, and the actuator fails when the torque of the electric motor is transmitted to the continuously variable transmission. Vehicle control device that detects whether or not The vehicle control device according to claim 2,
When the clutch control unit is normal,
The second clutch can be prevented from slipping with the torque transmitted from the continuously variable transmission, and the second clutch is slipped with the torque transmitted from the drive wheel before slippage occurs in the continuously variable transmission. A reference value for
A learning value for preventing the second clutch from slipping with a torque transmitted from the continuously variable transmission when a friction coefficient of the second clutch is reduced;
And the target value of the second clutch is controlled by adding the reference value and the learning value,
When the failure of the actuator is detected, the clutch control unit reduces the torque capacity of the second clutch by setting the learning value to zero.

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